Looking at the QVL for the ASUS ROG CrossHair Hero with AMD chipset x670E, shows that XMP memory is recommended - I thought only Expo was for AMD memory. I purchased a recommended XMP memory for this motherboard using this QVL, and the memory is extremely flaky, only working with one BIOIS version from last year, and certainly not achieving anything "fast" - 5600 MT/s.
So, is XMP supposed to be usable with x670E and the QVL is correct - I have a bad batch of memory, or is the QVL wrong and should only be showing Expo Memory Types, and I should buy one of those if I want better speeds and for my memory to work with most BIOS's ?
If these kits are on the QVL this means ASUS has tested them as working. XMP/EXPO are simply parameters input by the memory vendor onto an SPD table on the memory for the motherboard to address/assign.
The kits outlined are reasonable or mild frequency in terms of overclocking, however, no overclocking is gaurenteed and can depend on the CPU sample.
Try tuning the VSOC voltage or try XMP II profile if available as this may have more relaxed sub-timings.
Thanks for the answer, I actually swapped these out completely, bought 96GB of GSkill Trident Z5, with Expo written on the box, and based off of peoples posts saying this worked for their CPU and Motherboard setup (which is the same as mine).
I also updated to the latest BIOS, as the original sticks meant I had to stay on a year old BIOS. Now I'm on the latest and getting 5800 MT/s. I tried overclocking with the XMPI and XMPII in the BIOS but ahvent been able to boot unless I turn off all overclocking, on ther CPU also. I don't know why all these features exist in the BIOS with all these fancy names, becasue for the last 4 or 5 PCs I havent managed to over clock anything.